TLR4基因单核苷酸多态性与军团菌感染的体外实验研究

In vitro experimental of relationship between Toll-like receptor 4 single nucleotide polymorphism and Legionella infection

目的从体外实验探讨TLR4基因单核苷酸多态性TLR4(2244G→A)、(2299A→G)和(2242T→C)与军团菌感染的关系。方法用军团菌刺激健康人(n=54)外周血单个核细胞(peripheral blood mononuclear cell,PBMC),real-time RT-PCR检测PBMC中TLR4及My D88的表达水平,ELISA法检测培养上清液中IL-1β、IL-6及TNF-α的水平,采用SNa Pshot技术对TLR4多态性(2244G→A)、(2299A→G)和(2242T→C)进行分型检测。结果体外实验显示TLR4(2244G→A)AA型TNF-α表达显著高于GG/GA型(P=0.036 7),然而GG/GA型My D88、IL-6的水平显著高于AA型(P=0.035 2,P=0.031 7)。但是TLR4(A2299G)及TLR4(T2242C)各种基因型之间TNF-α、IL-6、IL-1β及TLR4、My D88的表达均无差异(P>0.05)。结论 TLR4基因单核苷酸多态性与军团菌感染的宿主易感性可能无关。

Objective To explore the association between Toll-like receptor 4 single nucleotide polymorphism（ SNP） 2244 G → A,2299 A→G,2242 T→C and the susceptibility of Legionella infection in vitro experimental research. Methods The peripheral blood mononuclear cells（ PBMC） from healthy subjects（ n = 54） were stimulated with L. pneumophila. Real-time RT-PCR was used to detect the mRNA expression level of TLR4 and My D88. The levels of TNF-α,IL-1 b and IL-6 were measured by enzyme-linked immunosorbent assay（ ELISA）. TLR4 genotyping was performed with SNa Pshot technology. Results In vitro assay results showed that the TNF-αexpression was significantly higher in TLR4（ G2244 A） AA than in GG/GA（ P = 0. 036 7）. The mRNA expression of My D88 and the level of IL-6 were significantly lower in TLR4（ G2244 A） AA than in GG/GA（ P = 0. 035 2,0. 031 7）. Whereas the expression of TNF-α,IL-6,IL-1β,TLR4 and My D88 showed no statistical difference among different genotypes of TLR4 A2299 G and TLR4 T2242 C polymorphism（ P 〉 0. 05）. Conclusion The findings indicate that there is no association about the TLR4（2244 G→A）,（2299 A→G）,（2242 T→C） polymorphism with susceptibility to L. pneumophila infection.